Vinyl benzyl ethers and nonionic water soluble thickening agents prepared therefrom

ABSTRACT

Nonionic water soluble thickening agents are prepared by copolymerizing about 1 to 5 mole percent of a vinyl benzyl ether having the formula ##STR1## and the balance to make 100 mole percent of acrylamide.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of our copending application Ser. No.489,876, filed July 18, 1974, now U.S. Pat. No. 3,963,684, which is adivision of our copending application Ser. No. 267,571, filed June 29,1972.

BACKGROUND OF THE INVENTION

This invention relates to improved nonionic water soluble thickeningagents and novel vinyl benzyl ether monomers to prepare same.

SUMMARY OF THE INVENTION

Accordingly the novel vinyl benzyl ether monomers have the formula##STR2## wherein R is hydrogen or methyl, m is about 10 to 100 and Y is##STR3## where R₁ is an alkyl, aralkyl or alkaryl hydrophobic group of10 to about 22 carbon atoms, R₂ is an alkyl group of 1 to about 22carbon atoms and R₃ is hydrogen or an alkyl group of 1 to about 22carbon atoms, provided R₂ and R₃ in combination have at least 10 carbonatoms.

The nonionic water soluble thickeners are prepared by copolymerizingabout 1 to 5 mole percent of said ether monomer or mixtures thereof andthe balance to make 100 mole percent of acrylamide.

DESCRIPTION OF THE INVENTION

The improvements obtainable by this invention are believed to be theresult of incorporating surface active groups as side groups from thecopolymer chain. Copolymers prepared with the monomers described in U.S.Pat. No. 3,190,925 do not provide the improved thickening action of thecopolymers described herein. Further, the vinyl benzyl ethers of thisinvention have and serve a totally different purpose than the monomersprepared and described in U.S. Pat. No. 3,190,925.

Vinyl benzyl ether monomers useful in this invention have the formula##STR4## where R, m and Y are as previously described. The monomers maybe prepared by reacting a vinyl benzyl halide having the formula##STR5## where R is as before and X is a halide, usually Cl or Br, witha nonionic surfactant having the formula ##STR6## where R, m and Y areas previously defined.

Generally, the nonionic surfactants are prepared by the condensation ofethylene oxide, propylene oxide or mixtures thereof with an alkyl,alkaryl, or aralkyl compound having one reactive hydrogen such as alkylphenols having the formula ##STR7## where R₄ is octyl, decyl, dodecyland the like; ##STR8## R₁ COOH; R₁ OH; R₁ SH; or ##STR9## where R₁, R₂and R₃ are as previously defined. Typical R₁ groups include lauryl,myristyl, cetyl, stearyl, oleyl, linoleyl, 2-phenyldecyl, octyl phenyl,nonyl phenyl and the like. R.sub. 2 and R₃ groups include methyl, ethyland other alkyl groups as defined for R₁. Alkyl phenol-ethylene oxidecondensates are preferably employed. It is desirable to employ nonionicsurfactants having little or no diol component to minimize formation ofdivinyl benzyl ethers. A variety of said nonionic surfactants and theirpreparation are fully disclosed in "Nonionic Surfactants," Vol. 1,edited by M. J. Schick, published by Marcel Decker, Inc. New York, 1967.

The number of oxyalkylene groups, ##STR10## as indicated by m should beat least 10 and may be quite large, up to about 100. The oxyalkylenegroups may be a mixture of oxyethylene and oxypropylene groups, eitherheteric or block, but it is preferred that all such groups beoxyethylene groups. Preferably the number of oxyalkylene groups is about20 to 40.

While the nonionic surfactants are well known as well as theirpreparation; the reaction of nonyl phenol with about 40 moles ofethylene oxide is described in the following example.

EXAMPLE 1

The starting nonylphenol was treated with 20 weight percent of tolueneand the toluene removed by distillation to azeotropically remove anyresidual water in the phenol and thereby minimize diol formation. Theethylene oxide contained less than 20 ppm of water by Karl Fischertitration.

In a 10 gallon stainless steel kettle was placed 2114 gms (9.6 moles) ofanhydrous nonyl phenol and the kettle purged with nitrogen. Sodium metal(42gms, 1.82 moles) was added and the kettle purged with nitrogen again.Sodium metal was used as a catalyst in place of NaOH to avoid formationof water during the reaction. The kettle was then vented to 0 lb gaugeand the contents heated at 100° C. for 1 hour. Ethylene oxide was thenadded continuously over six hours with the temperature maintained at100°-125° C. A total of 16,934 gms of ethylene oxide (380 moles or 40moles/mole of phenol) was added and the contents of the kettle allowedto react at 125° C. for 2 hours.

The product was then neutralized with CO₂ in the presence of 4 lbs ofwater which was subsequently removed by vacuum distillation usingtoluene to azeotropically remove the last traces of water. The productwas filtered to remove sodium carbonate. The final product weighed18,945 g, was a waxy solid melting at 43°-48° C., had a percent -OH byacetic anhydride titration of 0.8175%, and had a molecular weight of2080. For convenience the product will be designated nonyl phenol/40EO.

It is preferred in the above process to conduct the reaction at about50° to 180° C. at 5 to 150 psig oxide pressure, and more preferably at90° to 130° C. at 20-25 psig. The reaction is too slow below theselimits and side reactions occur above them. The catalyst concentrationgenerally is about 0.1 to 1% based on total weight of product. Most anyinorganic acid may be used for neutralization but CO₂ is preferredbecause no over-neutralization takes place.

EXAMPLE 2

Preparation of a Vinyl Benzyl Ether of Nonyl Phenol/40EO.

Into a nitrogen purged 2-gallon stainless steel kettle was charged 1512gms (0.727 mole) of nonyl phenol/40EO produced according to example 1,2415 gm of t-butyl alcohol as a solvent, and 16.4 gms of sodium metal(0.715 mole). The contents were heated at 100° C. for 2 hours while thepressure rose from 0 to 50 psig and leveled off. After cooling to roomtemperature, 107 gm of vinyl benzyl chloride (0.702 mole) was added. Thekettle purged with nitrogen and the contents heated at 50°-65° C. After3 3/4 hours a base titration showed 94% conversion of the vinyl benzylchloride to the vinyl benzyl ether. The contents were then heated anadditional 2 hours at 50°-55° C. and neutralized to pH 6-7 with 2.85 gmsof 95% acetic acid.

The alcohol solvent was removed by distillation until the kettletemperature was 80° C. and the pressure 20 mm Hg. One gallon of benzenewas added and then 1 quart distilled off to remove traces of alcohol.The slurry was filtered through filter cell at 175 mm Hg at 50° C. toremove NaCl and sodium acetate. Remaining benzene was removed bydistillation at 80° C. and 20 mm Hg. The waxy solid product had amelting point of 35°-40° C. and weighed 1530 gms. Bromide/bromatetitration in methanol gave an equivalent weight of 2180 gm/mole ofunsaturation.

t-Butyl alcohol is a preferred solvent because it results in goodreaction rates and yields. The reaction of vinyl benzyl chloride must bemaintained below about 65° C. to prevent polymerization in the stronglybasic medium. Since the salts formed are partially soluble in thealcohol, it is replaced by benzene prior to filtration. The salts areundesirable in the recovered product because they are detrimental topolymerization reactions. Benzene is preferred to other hydrocarbonsbecause it dissolves the product, doesn't dissolve the salts and is lowboiling and readily removed.

EXAMPLE 3

In a manner similar to example 2 the following vinyl benzyl ethermonomers were prepared. In all cases R was hydrogen and Y was -OR₁.

    ______________________________________                                        R.sub.1      m       Eq. Wt. per Double Bond                                  ______________________________________                                        A    methyl      20      1865                                                 B    n-octyl     10       768                                                 C    nonylphenyl 10       850                                                 D    n-octyl     40      2190                                                 E    n-decyl     40      2225                                                 F    n-dodecyl   40      2180                                                 G    nonyl phenyl                                                                              40      2400                                                 H    n-octadecyl 40      2560                                                 ______________________________________                                    

The above monomers were then used to prepare various acrylamidecopolymers.

EXAMPLE 4 Preparation of an Acrylamide-Vinyl Benzyl Ether Copolymer

The general procedure employed to prepare said copolymer was to dissolvethe monomers in a water-isopropanol solvent (80:20 wt. ratio) to make a10-15% monomer solution in 8 oz. citrus bottles. Ammonium persulfate(4000 ppm based on acrylamide) was added as catalyst. The bottles wereflushed with nitrogen, capped and the monomers allowed to polymerize at80° C. for 16 hours. The resulting viscous polymer solutions were thenused as thickeners. A homopolymer of acrylamide was prepared in the samemanner for comparative test purposes.

As previously indicated, the mole percent of the vinyl benzyl ether mayvary from about 1 to 5, preferably about 1 to 3, percent with thebalance to make 100 mole percent of acrylamide.

The following acrylamide/VBE copolymers were prepared according to theabove procedure. In each case, 15 gms of acrylamide and the appropriateamount of vinyl benzyl ether was dissolved in 135 gms of solvent.

    ______________________________________                                               Wt. of        Mole Ratio  % Polymer                                    Polymer                                                                              VBE*, gms     AA/VBE      in Solution                                  ______________________________________                                        1      8.02 (A)      .98/.02     14.6                                         2      3.3 (B)       "           11.7                                         3      3.66 (C)      "           12.2                                         4      9.42 (D)      "           15.2                                         5      9.57 (E)      "           15                                           6      9.38 (F)      "           15.2**                                       7      10.32 (G)     "           14.3                                         8      11.0 (H)      "           16.2**                                       9      3.97 (A)      .99/.01     12.3                                         10     1.64 (B)      "           11                                           11     1.81 (C)      "           11.1                                         12     4.67 (D)      "           12.7                                         13     4.74 (E)      "           12.8                                         14     5.12 (G)      "           13                                           15     --            1/0         10                                           ______________________________________                                         *Letter in () indicates which monomer from example 3 was used.                **Some gels formed in the polymerization which were removed by filtration                                                                              

EXAMPLE 5

The thickening ability of the various copolymers of example 4 wereevaluated in a commercially available acrylic latex (Rhoplex AC-34). Inthe tests with polymers 1 to 8, 40 gms of latex (46% solids) was dilutedwith water to 50 gms and 5-6 gms of the thickener solution added.Viscosity was measured on a Brookfield Viscometer using a No. 5 spindleat 50 rpm. With polymers 9-15, 50 gms of latex was used directly withoutany dilution.

    ______________________________________                                                  Wt. of Active    Viscosity,                                         Polymer   Thickener        cps                                                ______________________________________                                        1         0.73             40                                                 2         0.6              40                                                 3         0.6              900                                                4         0.6              40                                                 5         0.6              3,000                                              6         0.6              800                                                7         0.3              11,000                                             8         0.65             1,500                                              9         0.61             40                                                 10        0.55             60                                                 11        0.56             240                                                12        0.64             40                                                 13        0.64             1,600                                              14        0.26             8,800                                              15        0.5              120                                                ______________________________________                                    

The above results show a significant increase in viscosity of the latexwhen the number of carbons in the R₁ group was increased from 8 to 10and above. Without any thickener the viscosity of the latex was about 40cps.

EXAMPLE 6

To 50 gms of the latex, incremental amounts of thickener solution wereadded and the viscosity determined as before.

    ______________________________________                                                 Amt. of Active Viscosity                                             Polymer  Thickener      cps                                                   ______________________________________                                        10       0              40        cps                                                  0.132          40                                                             0.22           40                                                             0.34           40                                                             0.44           48                                                             0.55           60                                                    11       0.111          120                                                            0.222          140                                                            0.333          168                                                            0.444          200                                                            0.555          240                                                   12       0.127          40                                                             0.254          40                                                             0.317          40                                                             0.634          40                                                    13       0.127          288'                                                           0.254          560                                                            0.381          900                                                            0.508          1160                                                           0.635          1600                                                  14       0.065          520                                                            0.143          5600                                                  15       0.25           40                                                             0.5            120                                                   ______________________________________                                    

EXAMPLE 7

Following the procedure of example 2, vinyl benzyl ethers may beprepared from the following nonionic surfactants.

dodecylphenoxy (ethyleneoxy)₁₄ ethanol tridecyloxy (ethyleneoxy)₁₄ethanol stearyloxy (ethylenoxy)₁₉ ethanol lauryloxy (ethyleneoxy)₁₉ethanol dodecylmercapto (ethyleneoxy).sub. 9 ethanol t-alkyl (C₁₈ -C₂₂)amino (ethyleneoxy)₂₄ ethanol dialkylamino (ethyleneoxy)₄₀ ethanolN-methylstearamido (ethyleneoxy).sub. 40 ethanol N-ethyllauramido(ethyleneoxy).sub. 30 ethanol octadecylmercapto (ethyleneoxy).sub. 60ethanol N-methyl-N-dodecylamino (ethyleneoxy)₄₀ ethanol oleyloxyethyleneoxy)₃₅ ethanol hexadecylmercapto (ethyleneoxy).sub. 45 ethanolN,N-dioctylamino (ethylenoxy)₂₅ ethanol

Similarly, acrylamide copolymers may be prepared with vinyl benzylethers prepared from the above according to example 4.

What is claimed is:
 1. A nonionic water soluble binary copolymericthickening agent composed of in polymerized form about 1 to 5 molepercent of a vinyl benzyl ether monomer and the balance to make 100percent of acrylamide, said ether monomer having the formula ##STR11##wherein R is hydrogen or methyl, m is about 10 to 100 and Y is ##STR12##where R₂ is an alkyl group of 1 to about 22 carbon atoms and R₃ ishydrogen or an alkyl group of 1 to about 22 carbon atoms, provided R₂and R₃ in combination have at least 10 carbon atoms.
 2. The binarycopolymeric thickening agent of claim 1 wherein the mole percent of saidether monomer is about 1 to 3 percent.